R/pkgLoad.R

In rossholmberg/pkgButterfly: Functions to calculate relevant local oceanographic variables based on Afan et. al

#' activate the "install.packages" function, only if the package is not already installed,
#' then load that package
#'
#'
#' @param packages A vector of packages to be checked or installed.
#' Defaults to a list of my favourite packages, all worth having.
#' @param repos A character string, representing repository to be used if needed.
#' @param quietly TRUE or FALSE, should be suppress helper outputs?
#'
#' @keywords packages
#' @export

pkgLoad <- function( packages = "favourites", repos = "http://cran.csiro.au", quietly = TRUE ) {

  if( length( packages ) == 1L && packages == "favourites" ) {
    packages <- c( "data.table", "chron", "plyr", "ggplot2", "tibble",
                   "tidyr", "readr", "purrr", "dplyr", "shiny", "shinyjs",
                   "parallel", "foreach", "ggmap", "ggvis", "doMC",
                   "utils", "stats", "microbenchmark", "readxl", "feather",
                   "googlesheets", "DT", "knitr", "rmarkdown", "Rcpp",
                   "RcppArmadillo"
    )
  }

  packagecheck <- match( packages, utils::installed.packages()[,1] )

  packagestoinstall <- packages[ is.na( packagecheck ) ]

  if( length( packagestoinstall ) > 0L ) {

    # construct a feedback sentence, if requested
    if( !quietly ) {
      cat( "Installing packages " )
      for( i in seq_along( packagestoinstall ) ) {
        if( i != 1L ) {
          if( i == length( packagestoinstall ) ) {
            cat( " & " )
          } else {
            cat( ", " )
          }
        }
        cat( packagestoinstall[ i ] )
      }
      cat( paste0( " from ", repos, ".\n" ) )
    }

    utils::install.packages( packagestoinstall,
                             repos = repos
    )
  } else if( !quietly ) {
    cat( "All requested packages already installed." )
  }

  # Also make sure they're all loaded
  packages.to.load <- packages[ !( paste( "package", packages, sep = ":" ) %in% search() ) ]

  if( length( packages.to.load ) > 0L ) {
    if( !quietly ) {
      if( length( packages.to.load ) > 1L ) {
        cat( "Loading packages " )
      } else {
        cat( "Loading package " )
      }
    }

    for( i in seq_along( packages.to.load ) ) {
      if( !quietly ) {
        if( i != 1L ) {
          if( i == length( packages.to.load ) ) {
            cat( ", & " )
          } else {
            cat( ", " )
          }
        }
        cat( packages.to.load[ i ] )
      }
      suppressPackageStartupMessages(
        library( packages.to.load[ i ], character.only = TRUE, quietly = TRUE, logical.return = TRUE )
      )
    }

    if( !quietly ) { cat( ".\n" ) }

  }

}